When drive is transmitted to a set of rollers, wheels and or endless tracks with formations inside track to cooperate with teeth on a drive wheel or pulley, similar to as described in my earlier U.S. Pat. No. 7,464,429 and US 20040211450, this is typically done through various means of couplings or gears to drive either pulleys, belts and or tracks. There are various means of steering a track driven cleaner such as to provide braking force to one side, gear change mechanisms or flow diversion versions of which are described in my earlier U.S. Pat. No. 7,464,429, US 20040211450, US 2012/0060307 A1.
Common procedure to provide input to either side of track is to have an arrangement of pulleys or drive wheels where typical one pulley may be a toothed drive pulley where the teeth may coincide with formations on the inside of a track or belt that will in turn provide drive to other rollers or pulleys. A common occurrence if the track is in contact with pool surfaces may be that track can slide off the pulley especially when direction changes occur. Typically some form of rigid self-centering rib or otherwise may prevent such an occurrence, the addition of these rigid ribs in turn create high resistance hence higher power demand. Wear on tracks are also significant as the tracks are in constant contact with the pool surfaces and especially when steering changes occur the friction will accelerate wear significantly. Such track mechanisms are described in my earlier patents; also examples thereof such as shown in pat US 2011/0314617A1, where in conjunction with an endless track a method for direction change incorporates a similar method as described in my earlier U.S. Pat. No. 7,464,429 where 2 bevel gears are positioned at right angles to a third bevel gear and whereby alternating engagement, by means of a cam operated oscillatable assembly, from one bevel to the other will reverse direction of the cleaner.
US 2011/0314617A1 describes a version where an axially moveable output drive pulley changes position within the track every time a change of direction occurs. U.S. Pat. No. 7,464,429 describes a version where an oscillatable assembly will operate as a separate function to the track in terms the output or drive pulley stays in a fixed position within the track. A Problem with the arrangement of moving between bevel gears and normal gears are that as a function of the gear type there will be a transitional period where the gears are not engaged, typically then gear wear will be accelerated during the engagement and disengagement process, wear rate will depend on friction within the drivetrain as well as the speed of transition from one gear engagement to the other and vice versa. In my earlier U.S. Pat. No. 7,464,429 one method to assist with a quick transition is described. An alternative version of reversing and steering a cleaner by providing independent forward or reverse rotation to 2 output shafts either side of a cleaner by flow diversion as a means to overcome the gear wear issue is shown in my patent US 2012/0060307 A1.
Whereas the means for utilizing an oscillatable assembly to engage one of 2 gears is therefore not new, the method for doing so in a manner as described in this invention will overcome inherent wear problems by a significant factor in terms of the duration of the engagement process as well as the type of gear mechanism more suitable for engage and disengagement of gears coupled with a low friction drivetrain.